This has been a long time coming and while we might not have been active on the X3 section of these boards, we still were behind the scenes working on a perfect production level of our S58 flash lineup.
Entering the BMW re-flashing world back in 2009, we promised the community to deliver increased performance in a
Responsible manner, always leaning on the side of safety. Having years of education and experience in this field has taught us one thing: Cutting corners and using customers' vehicles as beta platforms might get you some good publicity, but will never result in a
Quality product. Every new platform we have tuned has always undergone Extensive testing on our own personal/company vehicles and only went public after being deemed safe, responsible and refined for general customers. Because of this, you can rest assured that every time you push that accelerator down, you are not playing Russian Roulette with your expensive pride and joy, but instead, you have sophisticated logic and countless hours of development running on your DME.
Without further ado, today we are presenting you guys with the full lineup of S58 flashing for F97/F98. The first set of lineup will include:
1)
Stage 1 for basic pump 91 octane: This package offers a 640bhp(570whp) power output and is designed to work with full stock hardware and Cali 91oct.
2)
Stage 1 for premium 93 octane: The lucky states that have access to 93octane at the pump will for sure enjoy a 670bhp(600whp) power output. Just like any stage 1, this is designed on fully stock hardware and being fed a regular pump 93 octane.
3)
Stage 1+ for E50 mixes: If 670bhp is not enough and you have access to E85, might we suggest mixing E85 into your fuel tank? The E50 flash is designed to work with E content between E35 to E60 and offers significant power increase to 715bhp(640whp).
4)
Stage 1+ for straight E85: Do you like the 700bhp+ power but just hate mixing in e85 and doing math each time you fill up? If so, Full E85 option might be just what you are looking for. With Full E85 option on Stage 1+, you are looking at even further power increase to 730bhp(650whp) combined with simplicity of filling up with E85 at all times and knowing that the flash logic will adjust for any content between E65 to E90.
Stage 2 mapping is left for vehicles with down-pipes. Once we do final dyno numbers on a vehicle with down pipes, the numbers will be updated on this thread.
Both of our base Stage 1 options are compatible with up to E25. Running E25 mixture will give you further power improvements with much more consistency.
Stage 1 (91-93) vs Stock
Stage 1+ (E50-E85) vs Stock
Notice that stock run here was actually ran on straight E85! We never ran a full stock of this car before all the tuning began and only realized that on the last day with a full tank of E85. So, to keep it as a reference, the "Stock" base run on the chars posted here is a fully original Timing/torque mapping but with custom fueling table that is designed to run full E85. Because the DME was able to hit full ignition targets with zero retard for octane, the stock power is about 10% higher then it would have been on 91oct. Still nice to see what this engine can put down stock with good octane!
And of course a quick draggy run with full tank, stock HW, 21" Conti on Stg1+ E85 flash.
Now lets talk about
behind the scenes! The age old question we get day in and day out is "What boost are you running?". As we have discussed this time after time on multiple threads, running target boost has been forgotten as a tuning strategy years ago. Instead, we run target torque. Since torque is a central figure in all of the MG1 DME functions, we decided to let the ECU run as engineered and control the boost with torque targets, with a little twist: giving throttle body a higher priority to control boost. It's a very hard thing to do but if done right, the result is just a smooth and steady load transition.
When it comes to controlling torque during load transition such as gear shift, there are two main ways of doing so:
1) Load Change Estimated -> Open WG -> Load Change Performed -> Close WG -> Wait for turbo to spool to desired airflow -> Control timing
2) Load Change Estimated -> Keep Turbo Spooled -> Lower Throttle Body and Cut Timing -> Load Change Performed -> Open Throttle Body and increase timing
Those two models are both used by BMW but for separate platforms. BMW uses model 1 for NON-M cars while they use model 2 for most of their M lineups as they have their own advantages that would be way too long to go into full detail here, though I'll explain why Model 2 is superior.
Anyone that has driven both M340i and X3M will point out right away how much longer it takes for the S58 to spool those turbos. That observation would be completely correct as S58 turbo layout is not ideal for low end torque and it takes a lot of exhaust flow to get those things pumping. Now, knowing that, you will clearly see why slowing down the turbos (as per model 1) is not ideal in events like gear shift as the result will be a momentary drop in power.
Now, lets look at model 2: We request a gear change and DME sees that as a load change about to to happen. DME keeps the WG relatively in similar position, closes Throttle body and controls valve lift to limit airflow into actual engine. The gearshift is performed, new higher torque target is set and DME opens up the TB to allow all the built up air in. This way, no waiting for turbos to spool, resulting in instant torque transition.
What does this all mean in very simple terms: Even thought we are requesting enough airflow to equate to 25psi(for example) of boost going into the actual combustion chamber, we are building up "Reserve" boost before throttle which is 3-5psi more.
Here is a datalog of the car running 10.75s with the Stg 1+ on full E85:
https://datazap.me/u/missiontuning/b...=21&zoom=4-240